WOLFRAM SYSTEM MODELER
InventoryForresterNormalNoiseInventory simulation with random orders |
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Diagram
Wolfram Language
In[1]:=
SystemModel["SystemDynamics.IndustrialDynamics.Inventory.InventoryForresterNormalNoise"]
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Information
Customer Demand Modeled as Noise
Customer demand usually fluctuates in a random fashion. Therefore, it is modeled in this simulation as normally distributed random noise with a mean value of mean=1000 and a standard deviation of stdev=100. The noise is sampled once per week and kept constant for the corresponding week. The order flow is modeled using the equation:
RRR(t) = RRRini + normal(1000,100);
Simulate the model across 10 years (520 weeks), and plot on a single graph the incoming orders, the production flow in the factory, and the levels of goods in retail, distribution, and the factory as functions of time:
Choose Radau-IIa as your integration algorithm. It handles noise input better than DASSL.
Parameters (3)
| RRRiniTop |
Value: 1000 Type: Real (1/wk) Description: Inital value of customer requests at retail |
|---|---|
| RRDiniTop |
Value: RRRiniTop Type: Real (1/wk) Description: Inital value of requisitions received at distribution |
| RRFiniTop |
Value: RRRiniTop Type: Real (1/wk) Description: Inital value of requisitions received at factory |
Outputs (5)
| randomNoise |
Type: Real (1/wk) Description: Random noise signal |
|---|---|
| factoryFlow |
Type: Real (1/wk) Description: Manufacturing flow at factory |
| retailStock |
Type: Real Description: Stock of goods in retail |
| distributionStock |
Type: Real Description: Stock of goods in distribution |
| factoryStock |
Type: Real Description: Stock of goods in factory |
Components (4)
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Factory1 |
Type: Factory Description: Factory model |
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Distribution1 |
Type: Distribution Description: Distribution model |
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Retail1 |
Type: Retail Description: Retail model |
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NoiseNormal1 |
Type: NoiseNormal Description: Normally distributed random noise |